1. She's a Friendly Ex: The blond beauty secretly dated Big Bang Theory costar Johnny Galecki for two years, and Cuoco only came clean about their relationship after they broke up. Despite still working together, Cuoco insists they've remained close friends and are always consummate professionals on set, "You hear about this all the time, costars date and then you have these horrible breakups," she said on The Talk. "And sometimes you just can't help it. We totally fell for each other and we just wanted to keep it private…We had an amazing relationship we were together for over two years…and it is a miracle and a blessing that we've both become the best of friends."

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2. She's Sporty: Cuoco was a nationally ranked amateur tennis player as a kid, a sport she took up when she was just 3 years old. She stopped playing when she was 16 in favor of pursuing her acting career, but she can still kick butt on the court. She also rides horses and kickboxes. Perfect for keeping up with the superfit Superman!

Courtesy Kaley Cuoco

3. She's a Relationship Girl: While discussing her onscreen relationship with costar Johnny Galecki, Cuoco dished on her own dating style, admitting she prefers to be in a relationship, "I can't handle the dating world," she said during an interview with a local news station. "I either have a boyfriend or I don't. There's no in between. It's one or the other." In addition to her romance with Galecki, Cuoco also dated addiction specialist Josh Resnick, with whom she was engaged to from Oct. to Mar. 2012. And she recently split with musician Bret Bollinger.

4. She's Been in the Acting Biz Since She Was a Kid: The 27-year-old actress starred in countless commercials as a little girl before she landed her first feature film appearance in the 1995 flick Virtuosity at just 10 years old. Cuoco also portrayed a young Ellen DeGeneres on the show Ellen, and in 2000, she played Marcia Brady in the TV movie Growing Up Brady, in which Adam Brody starred as her onscreen love. Just two years later, she landed her starring role on the hit ABC sitcom 8 Simple Rules before going on to portray Penny in The Big BangTheory, beginning in 2007.

Instagram

5. She's a Dog Lover: You won't find Kaley posting countless selfies on her Instagram, but you will find endless shots of her dogs. The actress has three rescue pit bulls who she proudly shows off on the social media site, and she's a huge proponent of rescuing pets. "I love them, I think they're the greatest dogs in the world, They are the friendliest, the sweetest," she gushed on The Ellen DeGeneres Show.

Who do you think of Cuoco and Cavill coupling up? Tell us in the comments!